I don't think this is correct, actually. object-cache.php doesn't call w3-total-cache/lib/W3/Cache/Apc.php directly. In fact, it first calls ObjectCache.php, and only from there does it call to Apc.php, Memcached, php, etc.
The order of params is actually correct once you look at set() in w3-total-cache/lib/W3/ObjectCache.php.
I did, however, just spent days on figuring out why object caching doesn't work reliably, and I have figured it out after much blood, sweat, and tears.
I'm going to post it separately, drop a link here, and attempt to get in contact with Frederick once again.